Seversk Technological Institute of National Research Nuclear University MEPhI

V. L. Sofronov, Professor, Dean of a Technological Faculty, e-mail: sofronov@ssti.ru

A. V. Anufrieva, Student

A. Yu. Makaseeva, Assistant Professor, Deputy Administrator

P. B. Molokov, Lecturer

I. Yu. Rusakov, Assistant Professor

Objective. Investigation of the processes of fluorination by elemental fluorine of iron oxides and rare-earth metals and also their mixtures.

Problems of the research. 1. To investigate the kinetics of fluorination by elemental fluorine of iron oxides and rare-earth metals and their mixtures as well. 2. To determine the optimum conditions of the process of fluorination.

Research methods. Kinetics of fluorination of metal oxides and their mixtures was studied on the thermogravimetric setup. Analyses and studies of the properties of raw materials and products were obtained with application of modern physical and chemical methods: the spectral-emission, atomic absorption, gas chromatography, and others.

Results. There have been given the results of the consideration of the thermodynamics and kinetics of fluorination studies of iron oxides and rare-earth metals and their mixtures. The experimental results are subjected to mathematical treatment by different models and it was found that the smallest mistake is given by the equation of the decreasing surface. The order of these reactions is close to 1 and the value of apparent activation energy of fluorination of neodymium oxides and iron Е_а = (87,0±7,0) kJ/mol and (43,0±3,0) kJ/mol respectively.

Conclusions. There have been considered the thermodynamics, kinetics of the fluorination process of iron oxides, and neodymium by element fluorine, and their mixtures, as well as the optimal conditions for these processes. It was established that these processes can be described by the Yander’s equation of decreasing surface, and their ratelimiting step is diffusion of the fluorinating agent and gaseous reaction products through a layer of solid material.

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